Kate Proctor, Westminster Correspondent

A PLAN to begin a temporary ceasefire in Syria within seven days is an ‘important step’ towards ending the civil war in the country, Foreign Secretary Philip Hammond has said.

Diplomats meeting at a summit in Munich agreed to seek a “nationwide cessation of hostilities” between Syrian government forces and rebel groups, US secretary of state John Kerry announced in the early hours of this morning.

Syrian walk at a camp near the Bab al-Salam border crossing with Turkey, in Syria, Saturday, Feb. 6, 2016. Thousands of Syrians have rushed toward the Turkish border, fleeing fierce Syrian government offensives and intense Russian airstrikes. Turkey has promised humanitarian help for the displaced civilians, including food and shelter, but it did not say whether it would let them cross into the country. (AP Photo/Bunyamin Aygun) TURKEY OUT

But it would not apply to extremist groups Islamic State (IS) and al-Nusra Front.

The agreement by world powers, including Russia, is the latest twist in a conflict which has killed an estimated quarter of a million people and displaced millions of refugees, many of whom have headed for Europe.

Mr Hammond welcomed the settlement but warned it would succeed only if Russia ceased bombing moderate opposition groups.

He said: “The International Syria Support Group (ISSG) meeting in Munich committed members to achieving a cessation of hostilities within a week, to delivering humanitarian assistance to named besieged communities by this weekend and to facilitating rapid progress in negotiations aimed at political transition.

A convoy of vehicles loaded with food and other supplies organized by The International Committee of the Red Cross, working alongside the Syrian Arab Red Crescent and the United Nations makes its way to the besieged town of Madaya in Syria, about 15 miles (24 kilometers) northwest of Damascus. (AP Photo)

“If implemented fully and properly by every ISSG member, this will be an important step towards relieving the killing and suffering in Syria. But it will only succeed if there is a major change of behaviour by the Syrian regime and its supporters.

“Russia, in particular, claims to be attacking terrorist groups and yet consistently bombs non-extremist groups including civilians. If this agreement is to work, this bombing will have to stop: no cessation of hostilities will last if moderate opposition groups continue to be targeted.”

Russian foreign minister Sergey Lavrov said Russian air strikes against terrorist groups would continue and again denied there had been strikes against civilians in rebel-held areas.

Mr Kerry said the proposed truce would depend on “whether or not all the parties honour those commitments and implement them”.

He described it as a “pause” in the long-running conflict but added a long-term solution depended on the Syrian government led by Bashar Assad and opposition groups engaging in “genuine negotiation” about the way forward.

However he admitted differences remain over the role Assad would play in Syria’s future.

Shadow foreign secretary Hilary Benn said: “Far too many lives have already been lost in Syria and a ceasefire is urgently needed to put an end to the bloodshed and bring in humanitarian aid.

“This announcement is a welcome step forward but the test will be whether it actually happens on the ground and if it includes an end to Russia’s bombing of the Syrian moderate opposition.”